In this poster, a new "split-screen"
adaptation of the preferential looking paradigm is introduced.
Because the stimuli are displayed on a single video monitor and
played from a standard VCR, this procedure allows for more controlled
and reliable presentation of stimuli than is often possible in
other instantiations of this paradigm.

INTRODUCTION

Preferential looking paradigms have had wide use within
the developmental literature to study topics ranging from infants'
visual acuity to their knowledge of bi-modal events, from infants'
visual expectancies to their acquisition of language. In particular,
within the field of language development, preferential looking
paradigms have met with considerable success in testing very
early language comprehension.Their principal advantages include:
1) tight control over experimental stimuli, 2) requiring no overt
action on the part of the child, and 3) allowing for presentation
of dynamic stimuli (enabling testing of verbs and predicates).
Unfortunately, this experimental power is often bought at the
expense of great technological expertise and effort, which can
lead to increased opportunity for experimental error.

ADVANTAGES

Tight control over presentation.

No overt action required.

Dynamic stimuli.

Portable & Cost Effective.

User Friendly.

Speed (Videos in less than a day).

STIMULI

"Do you see the shoe?"

METHOD

In this poster, a new "split-screen" adaptation
of the preferential looking paradigm was used. In it, two films
are presented simultaneously on one video monitor, one film on
the left side of the monitor and one film on the right side of
the monitor. Because the stimuli are now presented on a single
screen, the technological difficulties and expense inherent in
synchronizing multiple VCR's, as in previous two-screen paradigms,
are eliminated. This drastically reduces the potential for experimenter
error, provides for much finer synchronization of films, and
allows tighter control of other factors related to two monitors,
factors like brightness, tint, head position, etc. This procedure
also has the added benefit of shortening setup time and dramatically
reducing the overall cost of the method.

STUDY 1: 19 mo-olds

The new "split-screen" paradigm was validated
using the stimuli from an earlier 2-screen preferential looking
study of word endings in 19-month-olds (Golinkoff, Hirsh-Pasek,
& Schweisguth, in press). In that study and in the current
one, infants were shown pairs of films representing two actions
while one of the actions was requested. For example, infants
might see an actor "running" on the left side of the
screen and an actor "turning" on the right side while
simultaneously hearing an audio track requesting they look at
"running." Target verbs were counterbalanced, as was
the side of the match. The hypothesis, as in all preferential
looking procedures, was that infants will look longer at the
side displaying the matching action.

RESULTS

Infants (N=24; mean age = 19.4mo) did show
reliable looking preferences toward the film that matched the
requested verb. In addition, their looking times and responses
were very similar to the previous two screen version of this
task.

STUDY 2: 14 mo-olds

The "split-screen" paradigm was extended to a
younger age using two sets of nouns and verbs selected from the
Fenson, et. al., SRCD Monograph as words known to be part of
the vocabularies of young infants. In this manner, we hoped to
test children's knowledge of both object and action labels.
Thus, infants might see a car on the
left side of the screen and a shoe on the right side while simultaneously
hearing an audio track requesting they look at "shoe."
Conversely, as in the previous study, they might see a character
"hugging" on one side of the screen and "drinking"
on the other while the audio asked for "hugging."
Target words were again counterbalanced,
as was the side of the match. The hypothesis, once again, was
that infants would look longer at the side displaying the matching
word.

RESULTS

OBJECTS: LOOKING TO MATCH & NON-MATCH

ACTIONS: LOOKING TO MATCH & NON-MATCH

Infants (N=24, mean age=13.9mo) did show reliable looking
preferences toward the film that matched the requested object.
However, they did not show reliable preferences for action words,
although girls did show a trend in that direction.

DISCUSSION

As was found in previous two-screen studies, 19-month-old
infants indicated they understood action words. In addition,
14-month-olds demonstrated a competent understanding of nouns,
but only a tenuous grasp of verbs, at best. While these results
give reliable evidence for the development of the early lexicon,
they are most notable for their methodological implications.
The "split-screen" procedure
represents a new wave of controlled testing, despite reducing
the distances and size of the stimuli. More specifically, we
have a validation of how this paradigm can work for the study
of early language. Because this adaptation can replicate findings
in a more user friendly way with reduced technological complexity
and experimental error, it makes the preferential looking procedure
more accessible to researchers and practitioners alike.